This invention relates to a controlled deflection roll such as is used in the press and calender sections of a papermaking machine. More particularly, this invention relates to a non-self loading controlled deflection roll.
A typical controlled deflection roll includes a roll shaft having a longitudinal axis extending in a cross-machine direction. A roll shell surrounds the shaft. The shell engages another roll to apply a nip pressure. Due to the length of the controlled deflection roll in the cross-machine direction, the shell experiences some sag, or downward deflection, as a result of the weight of the shell and the applied nip load. The controlled deflection roll can be either self-loading or non-self loading. In a self-loading controlled deflection roll, the shell is translationally movable relative to the shaft by a hydraulic bearing pad so the nip will close when the bearing pad piston is pressurized. In a non-self loading controlled deflection roll, the shaft and the shell are radially fixed at their respective ends, and the entire controlled deflection roll is moved to close the nip. Typically, the non-self loading controlled deflection roll uses spherical roller bearings to support the ends of the shell relative to the shaft. The spherical roller bearings accommodate the relative deflection of the shaft and the shell.